﻿#region MIT Licence
/*
 * Copyright (C) 2014 PdfCreative
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software 
 * and associated documentation files (the "Software"), to deal in the Software without restriction, 
 * including without limitation the rights to use, copy, modify, merge, publish, distribute, 
 * sublicense, and/or sell copies of the Software, and to permit persons to whom 
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included 
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, 
 * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE 
 * AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#endregion

using System;
using System.Collections.Generic;
using System.Text;

namespace PdfCreative.Pdf.Writer.Utilities
{
    /// <summary>
    /// The ReflectionUtilities class is a static library class that provides convenience methods for reflecting
    /// type information.
    /// </summary>
    internal static class ReflectionUtilities
    {
        // Public methods
        // ==============
        #region Public methods
        /// <summary>
        /// Retrieves an instance of a class whose attribute matches the specified value. If no class was
        /// found to match the value, this method returns a Null reference.
        /// </summary>
        /// <typeparam name="T">The type to match</typeparam>
        /// <typeparam name="U">The attribute type</typeparam>
        /// <param name="match">The value to match the attribute's value against</param>
        /// <returns>An instance of the matching type.</returns>
        public static T GetMatchingInstance<T, U>(object match) where U : Attribute
        {
            T instance = default(T);

            foreach (Type type in typeof(T).Assembly.GetTypes())
                if(type.IsSubclassOf(typeof(T)))
                    foreach(U attr in type.GetCustomAttributes(typeof(U), false))
                        if (attr.Match(match))
                        {
                            instance = (T)type.Assembly.CreateInstance(type.FullName);
                            break;
                        }

            return instance;
        } // GetMatchingInstance()

        /// <summary>
        /// Retrieves an instance of a class whose attribute matches the specified predicate. If no class was
        /// found to match the value, this method returns a Null reference.
        /// </summary>
        /// <typeparam name="T">The type to match</typeparam>
        /// <typeparam name="U">The attribute type</typeparam>
        /// <param name="match">The value to match the attribute's value against</param>
        /// <returns>An instance of the matching type.</returns>
        public static T GetMatchingInstance<T, U>(Predicate<U> match) where U : Attribute
        {
            T instance = default(T);

            foreach (Type type in typeof(T).Assembly.GetTypes())
                if (type.IsSubclassOf(typeof(T)))
                    foreach (U attr in type.GetCustomAttributes(typeof(U), false))
                        if (match(attr))
                        {
                            instance = (T)type.Assembly.CreateInstance(type.FullName);
                            break;
                        }

            return instance;
        } // GetMatchingInstance()
        #endregion

    } // ReflectionUtilities class
}
